"Immunocytochemistry has proved to be a valuable diagnostic adjunct to cytopathologic diagnosis. The Cytopathology Section is involved in several clinically-related research projects, many of which utilize fine needle aspiration (FNA) and immunocytochemistry to provide ancillary diagnostic information regarding expression of various tumor antigens, HLA antigens or other markers. A partial listing of such studies includes: (1) Evaluation of percent of tumor cells expressing CD22 and CD19 in FNA specimens as part of a clinical trial using monoclonal antibody therapy for refractory lymphomas;(2) Cytologic diagnosis and immunophenotyping of ocular lymphomas; (3) characterization and application of a novel murine monoclonal antibody for malignant melanoma, MART-1 with subsequent quantitation of MART-1 in FNAs from malignant melanoma patients for treatment with anti-MART-1 antibody; (4) morphologic and immunocytochemical evaluation of bone marrow and peripheral blood samples for the detection of malignant cells in patients with stage IV breast cancer; (5) cytologic and immunocytochemical analysis of recently describeld antibodies for the differentialtion of malignant mesothelioma from adenocarcinoma;(6) Quantitation of CD3 positive lymphocytes in FNA specimens in malignant melanoma patients before and after immunotherapy;(7) utilization of cytokeratin antibodies in bone marrow and apheresis specimens for minimal residual disease and circulating tumor cell diagnoses in breast carcinoma patients.7) immunocytochemical evaluation of lymphoid populations in bronchoalveolar lavage specimens from patients subsequent to local exposure to endotoxin. ."